Protesters -- including some leftist lawmakers -- were battered and bloodied in a scuffle with riot police outside Mexico's Congress on Monday after supporters of presidential candidate Andres Manuel Lopez Obrador tried to set up a protest camp to demand a full recount in last month's election.
Lopez Obrador's backers also picketed the Federal Electoral Tribunal as it met to resolve election disputes, and maintained around-the-clock tent camps across large swaths of central Mexico City.
About eight protesters, including at least two federal lawmakers, were injured in the confrontation.
Later, the leftists briefly set up their encampment on a street further away from the Congress building as hundreds of riot police formed a line between them and the building, but then later appeared to abandon the camp.
"This is a state of siege, the rule of law has been broken, not by us but by the [government] institutions," said Aleida Alavez, a congresswoman-elect from Lopez Obrador's Democratic Revolution Party, or PRD, who took part in the protest.
Shouting "Vote by vote! Polling place by polling place!" the protesters briefly broke through a barrier and scuffled with police.
Later, officers were filmed beating several congressional Democratic Revolution representatives who tried to prevent tow trucks from hauling away three vehicles protesters had parked out front. Police then tried to remove the crowd, and some demonstrators threw stones, prompting police to fire back with tear gas.
The Federal Police said in a press statement that "a group of people blocked the entrances to the Congress building, impeding access to pedestrians and vehicles, and attempting to set up a camp to remain there."
The statement said police followed guidelines by trying to dialogue with the protesters, but that "given their refusal to withdraw, the federal police removed the blockade." Police called on the protesters to "demonstrate within the bounds of the law."
The PRD lawmakers later filed a complaint against police, and said Senator Elias Moreno Brizuela had suffered a rib injury, Congressman Juan Jose Garcia suffered minor head wounds, and three other legislators were apparently bruised or shaken.
"Not even in the worst era of the PRI did they do this," Moreno Brizuela said, referring to the Institutional Revolutionary Party, which ruled Mexico with a heavy hand from 1929 to 2000. "They attacked us and beat us."
Lopez Obrador told a rally later that "we won't allow ourselves to be provoked," adding "this is a message to intimidate us, but we are not cowards, Mr. President."
At news conference on Monday conservative presidential candidate Felipe Calderon called on Lopez Obrador "to reconsider his attitude." Calderon expressed confidence that he would ultimately be confirmed as the nation's next president.
Lopez Obrador has told his supporters to dig in for what could be years of demonstrations amid signs that a partial recount of the ballots is not going to reverse Calderon's slim lead in the official count.
Lopez Obrador contends that fraud was responsible for the official vote count that gave Calderon, of Fox's National Action Party, an advantage of about 240,000 ballots in the July 2 race. He has continued to demand a recount of all 41 million votes, but the Federal Electoral Tribunal ordered a recount in 9 percent of the polling places where it said there was evidence of irregularities.